The Changes of DDT Accumulation Metabolism,Liver Oxidative Stress and Structure Intervened by Moderate Intensity Exercise

Objective:To reveal the influence of aerobic exercise on DDT accumulation metabolic rules,changes of oxidative stress and structure in liver induced by DDT under the background of national fitness.Methods:90 male Wistar rats were randomly assigned into control group(CON),placebo group(PG),aerobic exercise group(AG),CON with DDT group(CDG)and aerobic exercise with DDT group(ADG).CDG and ADG were fed with DDT solution according to 40 mg/kg body weight for 2 weeks;ADG and AG were exercised with 18 m/min speed movement for 30 min every day.During 15 d,30dand 45 dafter exercise,DDT concentration was investigated by gas chromatography after grinding and freeze-drying and the distribution of DDT in different organizations were studied;the activities of SOD,GSH-Px and CAT were evaluated by xanthine oxidase method,enzyme kinetic method and visible light method respectively,the MDA content was determined with glucosinolates barbituric acid colorimetric method.The live samples were stained with HE for liver biopsy,and uranium acetate,citrate for liver ultrastructure,then observed and took photos with DP70 digital microscope imaging system and Tecnai Spirit transmission electron microscope and imaging system(120kv).Results:DDT concentrations decreased gradually in CDG liver,whereas it rose first and then fell in ADG liver.DDT concentrations in ADG liver were significantly higher than that in CDG from 15 dto 30d(P<0.01),and lower than the CDG at 45d(P<0.05).Compared with the CDG,DDT concentrations in ADG heart showed a significant rise at 15 dand 45d,and a significant decline at 30 d.DDT concentrations in CDG skeletal muscle decreased gradually but rose in ADG.From 15 dto 30d,DDT concentrations in ADG blood was significantly lower than that in CDG(P<0.01).DDT concentrations in CDG feces declined gradually but were relatively stable in ADG feces.Aerobic exercise can promote SOD activity in ADG from 15dto45 dwhich was significantly higher than that of the CDG(P<0.05),increase MDA content within 15-30dsignificantly(P<0.05)and decline it significantly after 30d(P<0.05),activate GSH-Px and CAT activity within 15 dand 30dafter feeding DDT(P<0.05)and inhibit it significantly at 45d(P<0.05).DDT intake affected liver ultrastructure,and the damage was aggravating with the accumulation of DDT.The changes of ultrastructure induced by DDT accumulation could be improved with aerobic exercise intervention(45d).Conclusion:Aerobic exercise can change the distribution of DDT in rats,reduce the concentration of DDT in liver,but increase the DDT distribution in heart and skeletal muscle during the early exercise period and increase the speed of DDT discharge for a long time exercise;Aerobic exercise can improve liver oxidative stress,particularly benefit the changes of oxidative stress at the early movement.Aerobic exercise is conducive to tissue recovery induced by the DDT enrichment.